Removal of microplastics and refractory humic/fulvic - like components from landfill leachate using Coagulative Colloidal Gas Aphrons: Insights on dissolved organic matter fingerprints

Microplastics (<5 mm) are one of the most persistent and emerging pollutants found ubiquitously in the natural environment. Still, identifying the source of these pollutants is lacking. Landfill leachates are known to be a major pathway to transmit them in the environment. Yet, removing these microplastics from leachate is being another challenging task. This research work investigates the removal of microplastics, metal ions and refractory organic pollutants from landfill leachate using a unique technique known as coagulative colloidal gas aphrons (CCGA). The target microplastics chosen for this study are polyethylene terephthalate (PET), polystyrene (PST), polypropylene (PPL) and polyethylene (PEL) microplastics. The property of metastable with superior stability of CCGA was confined by various parameters such as surfactant solution, Fe (III) dosages, microplastic quantities, zeta potential, kinetics and size of microbubble. The excitation - emission matrix results help to understand the occurrence and removal of refractory humic, fulvic and tryptophan components. The removal efficiency of COD and DOC was found to be 86 and 84%, respectively. Here we show that the electrostatic attraction plays a significant role in removing microplastics and coagulation mechanism such as bridging, adsorption and sweeping performs a major role in treating ion concentration present in the leachate solution.